Scale‐up Efficient Synthesis of <scp>α‐Poly</scp>(<i>L</i>‐lysine)^†

α-Poly(L-lysine) (α-PLL) is a water-soluble cationic biopolymer containing the monomeric unit α-L-lysine, which not only possesses excellent intrinsic properties but also can be modified via facile reactions between side amine groups and many other functional moieties. Ring-opening polymerization (ROP) most prevalently used technique for synthesis of PLL-based polypeptides, involves initial conversion ε-primary amine-protected α-L-lysine to L-lysine NCA monomer. However, obtaining N-carboxyanhydrides (NCAs) in high purity has been formidable challenge over 50 years, let alone large-scale synthesis. Herein, we show an unprecedented scale-up L-Cbz-LysNCA monomer its polymers, generating linear α-poly(L-lysine) with molecular weight (MW) up 13.4 kDa. This easy operated strategy will lay foundations industrial preparation further extend realm existing applications, offering paradigm polypeptides. Appendix S1: Supporting Information Please note: The publisher responsible content or functionality any supporting information supplied by authors. Any queries (other than missing content) should directed corresponding author article.